/// <summary>
/// Gets message from container.
/// </summary>
/// <param name="container">Container.</param>
/// <param name="key">Key.</param>
/// <returns>Hidden message.</returns>
public byte[] Extract(Container container, Key key)
{
if (!container.ContentType.Contains(Constants.IMAGE_CONTENT_TYPE))
throw new ArgumentException("LSB is only works with image containers.");
Bitmap bitmap = new Bitmap(container.InputStream);
byte[] bytes = new byte[key.MessageLength];
for (int y = 0; y < bitmap.Height; y++)
{
for (int x = 0; x < bitmap.Width; x++)
{
int number = x + y * bitmap.Width;
if (number >= key.MessageLength << 3)
{
return bytes;
}
Color pixel = bitmap.GetPixel(x, y);
extractDataFromPixel(number, pixel, bytes);
}
}
return bytes;
}
public static string ExtractDwm(IEmbeder embeder, ICryptor cryptor, Key key, Container container)
{
byte[] byteMessage = embeder.Extract(container, key);
Stream message = cryptor.Decrypt(StreamHelper.BytesToStream(byteMessage), key);
return StreamHelper.StreamToString(message);
}
public static Key GenerateKey(Container container, string message, CryptType cryptType, EmbedType embedType, IKeyAware keyParser, string stringkey)
{
if (!keyParser.ValidateKey(stringkey))
throw new ArgumentException("Key is not valid.");
Key key = new Key();
key.CryptType = cryptType;
key.EmbedType = embedType;
key.MessageLength = Constants.DEFAULT_ENCODING.GetByteCount(message);
key.Value = keyParser.ParseKey(stringkey);
return key;
}
public byte[] Extract(Commons.Container container, Key key)
{
return new byte[0];
}
public bool ValidateKey(Key key, Container container)
{
return key.CryptType == CryptType.DES && key.MessageLength == container.InputStream.Length;
}
public Stream Encrypt(Stream message, Key key)
{
DES DESkey1 = new DES();
FileProcessing fp = new FileProcessing();
MemoryStream ms = new MemoryStream();
fp.EnCryptFile(message, ms, cm1k, DESkey1.KeyList, null, null, 0, false);
return ms;
}
/// <summary>
/// Embeds DWM within container.
/// </summary>
/// <param name="cryptor">Crypt algorithm.</param>
/// <param name="embeder">Embeding algorithm.</param>
/// <param name="message">Secret message.</param>
/// <param name="key">Crypting key.</param>
/// <param name="container">Container.</param>
/// <param name="fileName">Container file name.</param>
/// <returns>Saved file name at server.</returns>
public static void EmbedDwm(ICryptor cryptor, IEmbeder embeder, string message, Key key, Container container)
{
Stream cryptedMessage = cryptor.Encrypt(StreamHelper.StringToStream(message), key);
embeder.Embed(container, StreamHelper.StreamToBytesArray(cryptedMessage));
}
public bool ValidateKey(Key key, Container container)
{
return true;
}
public Stream Encrypt(Stream message, Key key)
{
return message;
}
public System.IO.Stream Encrypt(Stream message, Key key)
{
return message;
}
